Commit d31faf65 authored Oct 28, 2013 by Ville Syrjälä

drm/i915: Fix scanoutpos calculations for interlaced modes

The scanline counter counts lines in the current field, not the entire
frame. But the crtc_ timings are the values for the entire frame. Divide
the vertical timings by 2 to make them match the scanline counter.

The rounding was carefully chosen to make it do the right thing wrt. the
observed scanline counter and ISR vblank bit behaviour.

Reviewed-by: <mario.kleiner.de@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

parent 3c184f69

drivers/gpu/drm/i915/i915_irq.c

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -698,6 +698,12 @@ static int i915_get_crtc_scanoutpos(struct drm_device *dev, int pipe,
	vbl_start = mode->crtc_vblank_start;		vbl_start = mode->crtc_vblank_start;
	vbl_end = mode->crtc_vblank_end;		vbl_end = mode->crtc_vblank_end;

			if (mode->flags & DRM_MODE_FLAG_INTERLACE) {
			vbl_start = DIV_ROUND_UP(vbl_start, 2);
			vbl_end /= 2;
			vtotal /= 2;
			}

	ret \|= DRM_SCANOUTPOS_VALID \| DRM_SCANOUTPOS_ACCURATE;		ret \|= DRM_SCANOUTPOS_VALID \| DRM_SCANOUTPOS_ACCURATE;

	/*		/*